$ git clone -n https://src.fedoraproject.org/rpms/perl-Hash-FieldHash.git /var/lib/mock/f43-perl-60959234-6586775/root/chroot_tmpdir/scmroot/perl-Hash-FieldHash
Cloning into '/var/lib/mock/f43-perl-60959234-6586775/root/chroot_tmpdir/scmroot/perl-Hash-FieldHash'...
$ git fetch origin f21ff8afac3d5e10987184018bdf3b10b62dfc21:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Hash-FieldHash
 * [new ref]         f21ff8afac3d5e10987184018bdf3b10b62dfc21 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f21ff8a Perl 5.42 rebuild